Create gameobject in hierarchy on Unity refresh but before Play mode

How can I create a gameobject just by adding a prefab, for example when you have an empty hierarchy and you add a Canvas gameobject it will automatically add an EventSystem gameobject, is it possible to create a prefab that when add in the hierarchy it will automatically create other gameobjects or prefabs? Please note that this is not something that you can have it on awake or start since this will happen even before you press the play button in editor.